Icom R75 Performance Upgrades

Kiwa Upgrades The
following Upgrades are available by sending the R75 to Kiwa
Electronics. Please note that Kiwa also provides other services and modifications to the R75 other then the listed upgrades below. These include custom audio bandwidths, installation of the High Stability Crystal and modification of the Speech Module for higher audio output. If you have a special request, please feel free to contact us.

Synchronous
Detector UpgradePlease Note: The Sync Detector upgrades requires the Icom Sync Detector hardware and software be
installed.
New R75's do not have the required circuitry and installed software.

Kiwa provides two major upgrades to the
Synchronous Detector. Together they provide enhanced performance where
the PLL stays "locked" under the most difficult signal conditions.The
first upgrade is best described as a "dual speed control voltage". The
control voltage for the PLL filter is tuned within an optimum window
that is determined by signal conditions.The response is slow to maintain
a "centered" condition. A second circuit provides the control accuracy
to react to fast flutter fading and noisey conditions. These two
circuits provide a dual speed control for the PLL. The second major
upgrade is to the Synchronous AM AGC. The dual speed technique is used
again to first center the AGC but still allow for quick short changes in
AGC characteristics as required by signal conditions. All components are
encapsulated in a plastic module and mounted to a side chassis
wall.

Synchronous Detector Upgrade
$45.00

Note: This price is for the Sync Module installed by Kiwa. If you wish to purchase the Sync Module as a kit, see below.

Audio Upgrade Key components to
the audio power amplifier are replaced to enhance audio
definition.The end result is improved intelligibility where consonants like c's, k's and q's have improved clarity.
Audio Upgrade $40.00

The R75 has an inline audio filter that preceeds the audio power amplifier.
The audio filter comes stock with a bandwidth of 3 kHz.
The High Fidelity Audio Filter Upgrade extends the audio bandwidth to 4.3 kHz. This upgrade is similar to dr. phil's
upgrade as presented on the R75 Yahoo Group. The difference
between dr. phil's upgrade
and Kiwa's is that we set the audio bandwidth to 4.3 kHz while dr. phil extends the audio bandwidth to 5.5 kHz. We adopted
the 4.3 kHz because we felt it was more in line with the filters offered and to
provide some attenuation to 5 kHz hetrodynes which can be a problem on the SW bands (due to the 5 kHz channel spacing
between stations)High Fidelity Audio Filter Upgrade $40.00

AM BCB RF Attenuator DisableThe R75 like many other Icom receivers has an antenna input RF attenuator for
the AM Broadcast Band. This attenuator in technical terms is called a 50 ohm pi
or delta resistive pad. Total attenuation is only 3 dB. Kiwa offers two solutions to disable this attenuation (a slight
improvement in AM BCB sensitivity will result). The most cost effective solution is
our simple but partial removal of the resistive pad. This results in a 1.5 dB signal improvement. The cost for the partial
removal is $5.00.Full removal of the resistive pad is much more complex.
The cost for complete removal (which will result in a 3 dB signal increase - or a 1.5 dB improvement over the partial disable)
is $25.00.This price includes the cost of parts.

Main Tuning Encoder repairIf the Main Tuning Knob is erratic or stopped working, the encoder requires repair. The R75 shares the same encoder as the Icom 756 and other newer Icom receivers. $80.00

RF AGC ModThe AGC has two speeds, fast and slow. However as designed the difference between the two AGC
settings is minimal. Engaging the slow position only slightly lengthens the release time.
This mod provides a marked difference between the fast and slow positions where the slow AGC is lengthened with dual time
constant circuitry.RF AGC Mod $20.00

UT-106 DSP Board InstallationIf you have purchased the UT-106 DSP board and wish Kiwa to install it, the cost for
installation is $15.00.

R75 Filter Module
The Kiwa R75 Filter Module is a substitute for Icom's FL-257 (3.3 kHz BW) filter option using the Kiwa "Blue Dot" filter.
The -6 dB bandwidth will vary from 6.5 kHz to 7.0 kHz with a nominal bandwidth of 6.8 kHz.
The module plugs into the the main board like the FL-257 at the Option 2 filter slot. Full set-up instructions are included
to assign the filter module to either the wide or intermediate filter position.R75 Filter Module Kit $40.00
Shipping and Handling within North America $8.00

Synchronous Detector
Upgrade Kit The
Sync Detector module as described above is supplied with installation instructions.
Please be aware that a fine tipped soldering iron and good eyes are
absolutely required to properly install this sync
module.Synchronous Detector Upgrade Kit $35.00
Shipping and Handling within North America $8.00

Note: If you order both the Sync Module and Filter Module, the Shipping and Handling would be $8.00 total.